1. Field of the Invention
The present invention relates to a radio communication system, a radio communication method, and a gateway, and more particularly to a radio communication system, a radio communication method, and a gateway, such as a mobile communication system having an M2M (machine-to-machine) mobile gateway.
2. Related Art
A related art mobile system includes a mobile station MS, a base station BS, and a mobile gateway GW (ASN-GW in a WiMAX system). When the MS conduct a communication, the MS is connected to the GW such as the mobile GW through the BS, and accesses to the Internet through the mobile GW. The MS is in an active or idle state according to a communication state. The active state represents a data communicating state, and the idle state represents a standby state in which no communication is conducted, and a communication can be restarted. The mobile GW always holds the MS information on the active state and idle state, thereby enabling the data communication, or a return from the standby state to the communication state.
Also, in recent years, with the development of an information communication network and a communication technique, attention is paid to an M2M communication in which a communication is conducted between the respective machines connected to each other through a network without intervention of a person. In particular, in a social infrastructure such as electric power, water, or gas, a meter (smart meter) having a communication function has appeared.
JP-T-2011-524136 discloses a method and a device used in the M2M communication system.
In general, the mobile communication system has a tree structure. Hereinafter, an example of the mobile communication system having the tree structure will be described.
FIG. 24 is a configuration diagram of a related art mobile communication system.
The mobile system includes a mobile station (MS) 500, base stations (BSs) 400 to 403, access service network gateways (ASN-GWs) 200 and 201 that manage the BSs, and a home agent (HA) 300. The HA 300 supports a mobile IP. The HA 300 is connected to an Internet 700 when the HA 300 provides an internet service.
FIG. 25 is a diagram illustrating an idle migration sequence in the related art mobile communication system. The MS 500, the BS 400, the ASN-GW 200, and the HA 300 transfer messages to each other in conformity to a rule. A radio path 510 is established between the MS 500 and the BS 400. A path 410 such as a generic routing encapsulation (GRE) capsuling path is established between the BS 400 and the ASN-GW 200. A path 310 is established between the ASN-GW 200 and the HA 300. Data connection is conducted by those paths. When the MS 500 requests deletion (idle migration) of the MS information, the MS 500 transmits a deletion request (DREG-REQ 800) to the BS 400 whereby the BS 400 transmits an idle mode entry state change request (IM_Entry_State_Change_Req. 801) to the ASN-GW 200. Thereafter, messages are transferred according to the rule to execute an idle migration sequence (delete sequence) (IM_Entry_State_Change_Rsp. 803, DREG-CMD 802, IM_Entry_State_Change_Ack. 804, Path_Dereg_Req. 805, Path_Dereg_Rsp. 806, and Path_Dereg_Ack. 807). As a result, the ASN-GW 200 holds the MS information, and manages the MS 500 as the idle state.
FIG. 26 is a diagram illustrating an active migration sequence in the related art mobile communication system. A path 310 is established between the ASN-GW 200 and the HA 300 to conduct the data connection. When the MS 500 requests registration (active migration) of the MS information, the MS 500 transmits a registration request (REG-REQ 810) to the BS 400 whereby the BS 400 transmits an idle mode exit state change request (IM_Exit_State_Change_Req. 811) to the ASN-GW 200. Thereafter, messages are transferred according to the rule to execute an active migration sequence (registration sequence) (IM_Entry_State_Change_Rsp. 812, IM_Entry_State_Change_Ack. 813, Path_Dereg_Req. 814, Path_Dereg_Rsp. 815, REG-RSP 816, CMAC_Key_Count_Update 817, CMAC_Key_Count_Update_Ack. 818, Path_Reg_Ack. 819). As a result, the ASN-GW 200 makes a management state of the MS 500 active. Also, the MS 500, the BS 400, the ASN-GW 200, and the HA 300 transfer the messages to each other according to the rule. A radio path 511 is established between the MS 500 and the BS 400, a path 411 such as a generic routing encapsulation (GRE) capsuling path is established between the BS 400 and the ASN-GW 200 to conduct the data connection.